1#ifndef _ALPHA_ATOMIC_H 2#define _ALPHA_ATOMIC_H 3 4#include <linux/types.h> 5#include <asm/barrier.h> 6#include <asm/cmpxchg.h> 7 8/* 9 * Atomic operations that C can't guarantee us. Useful for 10 * resource counting etc... 11 * 12 * But use these as seldom as possible since they are much slower 13 * than regular operations. 14 */ 15 16 17#define ATOMIC_INIT(i) { (i) } 18#define ATOMIC64_INIT(i) { (i) } 19 20#define atomic_read(v) ACCESS_ONCE((v)->counter) 21#define atomic64_read(v) ACCESS_ONCE((v)->counter) 22 23#define atomic_set(v,i) ((v)->counter = (i)) 24#define atomic64_set(v,i) ((v)->counter = (i)) 25 26/* 27 * To get proper branch prediction for the main line, we must branch 28 * forward to code at the end of this object's .text section, then 29 * branch back to restart the operation. 30 */ 31 32#define ATOMIC_OP(op) \ 33static __inline__ void atomic_##op(int i, atomic_t * v) \ 34{ \ 35 unsigned long temp; \ 36 __asm__ __volatile__( \ 37 "1: ldl_l %0,%1\n" \ 38 " " #op "l %0,%2,%0\n" \ 39 " stl_c %0,%1\n" \ 40 " beq %0,2f\n" \ 41 ".subsection 2\n" \ 42 "2: br 1b\n" \ 43 ".previous" \ 44 :"=&r" (temp), "=m" (v->counter) \ 45 :"Ir" (i), "m" (v->counter)); \ 46} \ 47 48#define ATOMIC_OP_RETURN(op) \ 49static inline int atomic_##op##_return(int i, atomic_t *v) \ 50{ \ 51 long temp, result; \ 52 smp_mb(); \ 53 __asm__ __volatile__( \ 54 "1: ldl_l %0,%1\n" \ 55 " " #op "l %0,%3,%2\n" \ 56 " " #op "l %0,%3,%0\n" \ 57 " stl_c %0,%1\n" \ 58 " beq %0,2f\n" \ 59 ".subsection 2\n" \ 60 "2: br 1b\n" \ 61 ".previous" \ 62 :"=&r" (temp), "=m" (v->counter), "=&r" (result) \ 63 :"Ir" (i), "m" (v->counter) : "memory"); \ 64 smp_mb(); \ 65 return result; \ 66} 67 68#define ATOMIC64_OP(op) \ 69static __inline__ void atomic64_##op(long i, atomic64_t * v) \ 70{ \ 71 unsigned long temp; \ 72 __asm__ __volatile__( \ 73 "1: ldq_l %0,%1\n" \ 74 " " #op "q %0,%2,%0\n" \ 75 " stq_c %0,%1\n" \ 76 " beq %0,2f\n" \ 77 ".subsection 2\n" \ 78 "2: br 1b\n" \ 79 ".previous" \ 80 :"=&r" (temp), "=m" (v->counter) \ 81 :"Ir" (i), "m" (v->counter)); \ 82} \ 83 84#define ATOMIC64_OP_RETURN(op) \ 85static __inline__ long atomic64_##op##_return(long i, atomic64_t * v) \ 86{ \ 87 long temp, result; \ 88 smp_mb(); \ 89 __asm__ __volatile__( \ 90 "1: ldq_l %0,%1\n" \ 91 " " #op "q %0,%3,%2\n" \ 92 " " #op "q %0,%3,%0\n" \ 93 " stq_c %0,%1\n" \ 94 " beq %0,2f\n" \ 95 ".subsection 2\n" \ 96 "2: br 1b\n" \ 97 ".previous" \ 98 :"=&r" (temp), "=m" (v->counter), "=&r" (result) \ 99 :"Ir" (i), "m" (v->counter) : "memory"); \ 100 smp_mb(); \ 101 return result; \ 102} 103 104#define ATOMIC_OPS(opg) \ 105 ATOMIC_OP(opg) \ 106 ATOMIC_OP_RETURN(opg) \ 107 ATOMIC64_OP(opg) \ 108 ATOMIC64_OP_RETURN(opg) 109 110ATOMIC_OPS(add) 111ATOMIC_OPS(sub) 112 113#undef ATOMIC_OPS 114#undef ATOMIC64_OP_RETURN 115#undef ATOMIC64_OP 116#undef ATOMIC_OP_RETURN 117#undef ATOMIC_OP 118 119#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) 120#define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) 121 122#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) 123#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) 124 125/** 126 * __atomic_add_unless - add unless the number is a given value 127 * @v: pointer of type atomic_t 128 * @a: the amount to add to v... 129 * @u: ...unless v is equal to u. 130 * 131 * Atomically adds @a to @v, so long as it was not @u. 132 * Returns the old value of @v. 133 */ 134static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) 135{ 136 int c, new, old; 137 smp_mb(); 138 __asm__ __volatile__( 139 "1: ldl_l %[old],%[mem]\n" 140 " cmpeq %[old],%[u],%[c]\n" 141 " addl %[old],%[a],%[new]\n" 142 " bne %[c],2f\n" 143 " stl_c %[new],%[mem]\n" 144 " beq %[new],3f\n" 145 "2:\n" 146 ".subsection 2\n" 147 "3: br 1b\n" 148 ".previous" 149 : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c) 150 : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u) 151 : "memory"); 152 smp_mb(); 153 return old; 154} 155 156 157/** 158 * atomic64_add_unless - add unless the number is a given value 159 * @v: pointer of type atomic64_t 160 * @a: the amount to add to v... 161 * @u: ...unless v is equal to u. 162 * 163 * Atomically adds @a to @v, so long as it was not @u. 164 * Returns true iff @v was not @u. 165 */ 166static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) 167{ 168 long c, tmp; 169 smp_mb(); 170 __asm__ __volatile__( 171 "1: ldq_l %[tmp],%[mem]\n" 172 " cmpeq %[tmp],%[u],%[c]\n" 173 " addq %[tmp],%[a],%[tmp]\n" 174 " bne %[c],2f\n" 175 " stq_c %[tmp],%[mem]\n" 176 " beq %[tmp],3f\n" 177 "2:\n" 178 ".subsection 2\n" 179 "3: br 1b\n" 180 ".previous" 181 : [tmp] "=&r"(tmp), [c] "=&r"(c) 182 : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u) 183 : "memory"); 184 smp_mb(); 185 return !c; 186} 187 188/* 189 * atomic64_dec_if_positive - decrement by 1 if old value positive 190 * @v: pointer of type atomic_t 191 * 192 * The function returns the old value of *v minus 1, even if 193 * the atomic variable, v, was not decremented. 194 */ 195static inline long atomic64_dec_if_positive(atomic64_t *v) 196{ 197 long old, tmp; 198 smp_mb(); 199 __asm__ __volatile__( 200 "1: ldq_l %[old],%[mem]\n" 201 " subq %[old],1,%[tmp]\n" 202 " ble %[old],2f\n" 203 " stq_c %[tmp],%[mem]\n" 204 " beq %[tmp],3f\n" 205 "2:\n" 206 ".subsection 2\n" 207 "3: br 1b\n" 208 ".previous" 209 : [old] "=&r"(old), [tmp] "=&r"(tmp) 210 : [mem] "m"(*v) 211 : "memory"); 212 smp_mb(); 213 return old - 1; 214} 215 216#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) 217 218#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) 219#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) 220 221#define atomic_dec_return(v) atomic_sub_return(1,(v)) 222#define atomic64_dec_return(v) atomic64_sub_return(1,(v)) 223 224#define atomic_inc_return(v) atomic_add_return(1,(v)) 225#define atomic64_inc_return(v) atomic64_add_return(1,(v)) 226 227#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) 228#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0) 229 230#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) 231#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0) 232 233#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 234#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0) 235 236#define atomic_inc(v) atomic_add(1,(v)) 237#define atomic64_inc(v) atomic64_add(1,(v)) 238 239#define atomic_dec(v) atomic_sub(1,(v)) 240#define atomic64_dec(v) atomic64_sub(1,(v)) 241 242#endif /* _ALPHA_ATOMIC_H */ 243